Treatment of perchlorate contaminated water using an advanced membrane reactor

The perchlorate contamination of drinking water has become a major concern for many areas of the country. Hence, effective and reliable treatment technology is needed at water treatment plants to treat perchlorate below the local regulatory limits. This research was particularly important because it addresses specific concerns of using the advanced membrane reactor (AMR) in the water treatment plant. The advantages of using hydrogenotrophic perchlorate treatment over heterotrophic treatment include: (1) lower cell yield; (2) elimination of carryover of added organic electron donor to the product water; (3) the relatively low solubility of hydrogen, which makes it easy to remove from the product water by air stripping; and (4) the low cost of hydrogen.

The major objectives of the research were (1) to develop an autotrophic membrane bioreactor for treating perchlorate contaminated water; (2) to determine the suitability of the treatment unit in water treatment plants with respect to biomass washouts; and (3) to determine the kinetics of perchlorate degradation. From the kinetics data, the reactor for the water treatment plant can be appropriately sized for the influent perchlorate concentration. Various experiments were conducted using distilled, deionized (DDI) water and tap water as the feed solution. DDI water feed was used to confirm that the culture growing in the reactor was autotrophic. The AMR was successful in treatment of perchlorate contaminated water regardless of the type of the feed used. The efficiency of AMR was observed to be greater than 99.9% in treating the perchlorate to less than detection limit levels (4 ìgl).